. >> i want to make it absolutely clear to assad and those under his command the world is watching. the use of chemical weapons is and would be totally unacceptable. if you make the tragic mistake of using these weapons, there will be consequences, and you will be held accountable. >> reporter: a senior official tells abc news there are contingency plans for military action if the weapons became a threat. the syrian regime said it would not use chemical weapons under any circumstance, but president ass assad's father used them, and assad himself has been massacring his citizens for nearly two straight years. martha raddatz, abc news, washington. >> it's a little hard to believe since tens of thousands of folks have been killed already, use of chemical weapons would be off limits to the syrian regime right now. considering rebels have made advances that may be one of the most powerful weapons the government has in its arsenal right now. again, that's a red line according to the u.s. if chemicals are used, that could draw us into this conflict militarily. that is a whole different lev